Spring construction



Nov. 24, 1953 F, 5 LAURlE 2,660,227

SPRING CONSTRUCTION Filed June 18, 1949 Patented Nov. 24, 1953 SPRING CONSTRUCTION Floyd S. Laurie, Royal Oak, Mich., assignor to American Metal Products Company, Detroit, Mich., a corporation of Michigan Application June 18, 1949, Serial No. 99,925

1 Claim.

This invention relates to spring constructions embodying zigzag or sinuous spring strips of the type disclosed and claimed in Kaden Reissue Patent No. 21,263.

Spring constructions of the type referred to have become increasingly popular in recent years because of their economy in manufacture and also because of the diversity of spring characteristics and cushioning effects which can be obtained with them by altering the nature of the individual spring strips. The present invention constitutes another development in sinuous spring strips which further emphasizes the aforementioned features of economy and diversity of spring characteristics, it being the particuiar object of the invention to provide a helper spring for stiffening the load supporting portion of' a sinuous spring strip.

The invention is illustrated in the accompanying drawings in which:

Figure l is a perspective View of a seat end back spring cushion construction with a part of the back broken away to reveal a strip constructed according to the principles of this invention; i y

Fig. 2 is a front elevation of the back cushion of Fig. 1 with the fabric and covering material removed to show a plurality of spring strips of the invention attached to upper and lower support rails; and

Fig. 3 is a cross section taken on line 3--3 of Fig. 2.

The body rest construction l of Fig. 1 comprises a seat cushion 3 and a back cushion 5, each of which preferably contains spring strips embodying features of this invention. In the back cushion, which is selected to illustrate one application of the present invention, the sinuous or zigzag strips 'i are, in the conventional manner, parallel and laterally spaced and each `connected at its ends to the top and lower support rails 9 and ll, respectively, of the back panel l2 by insertion of the endmost lateral straight portions of the strips in suitable spring supporting clip strips i3 that are tightly secured to the rails.

The strips 'l are made of two pieces of sinuous strips which are pre-arched and constructed in accordance with the aforementioned Kaden Reissue Patent No. 21,263. The rst strip l5 has a web il and integral supports for the web Il which each comprise an inwardly bent arm I9 and then an arm 2l which is outwardly and reversely bent from the arm I9 and secured by the strips I3 to the rails 9 and Il in the manner 2 already described. The web il is arched so as to provide a crown or downwardly presenting arc, though, as shown by the dotted lines, it is originally pre-arched on a smaller radius than that which it has after assembly to the rails. The arms 2i also preferably are formed to provide downwardly presenting arcs, but the arms i9 are preferably straight or upwardly presenting in the strip l5 per se.

The second member of the strip l is the helper spring 2l. This member, which is of approximately the same length as the web ll, is, as shown in dotted lines, pre-arched on a smaller radius than that which it has after assembly to spring l5. Intermediate portions of the helper spring 2l are secured by clips 2S to the web il so that the helper spring continuously engages the underside of the major load supporting portion of the web Il'. The ends of the helper spring are secured by clips 3| to intermediate points of the arms i9, these connections preferably being made in such a manner as to reverse the crown of the arms i9 whereby they assume the shape of downwardly presenting arcs.

It will now be recognized that the helper spring 2 serves to stiien the load supporting portion of the web il, i. e., the portion between clips 29, and yet permits the end portions of the web ll beyond the clips 29 to remain relatively soft. The degrees of stiffening and softness remaining can, of course, be regulated by varying the spacing of the clips 29 and by varying the proximity of the clips 3l to the ends of the web Il', the guiding consideration being that softness increases as the radius of curvature or flatness of the helper spring.

While the preferred form of spring strip l has been illustrated, it will be appreciated that the helper spring 2l may be used in conjunction with other forms of springs l5, hence it is not intended to limit the invention to the specific structure herein shown.

What is claimed is:

A sinuous spring strip comprising a iirst spring member made of wire bent back and forth in sinuous form having a web and integral supports for the web bent in the shape of a V thereunder, one of said supports comprising a first portion continuous with the web that is reversely bent inwardly under the web and a second portion reversely bent outwardly from the rst portion and adapted at its end to be secured to a rail, and a second helper spring member also made of wire bent back and forth in sinuous form for stiffening the load supporting portion 3 of the web disposed on the underside of the web and secured to an intermediate portion thereof and having end portions secured to intermediate points of the support, both said he'lper spring and said web being in the form of downwardly presenting arcs, said helper spring connection with the one support being to anY intermediate point of the rst portion, when connected to the. web the length of the helper spring portion included between the web and the rst portion of the one support being less than the distance between the first portion and web wit-hout such connection whereby said connection of the. rst

portion and helper spring results in. upward` crowning of the first portion, the iirstY portion thus being in the form of a downwardly presenting arc.

FLOYD S.

References Cited in the le of this patent UNITED STATES PATENTS Number Esiti-mixerV Name Date Hollings Nov. 19, 1872 Baldwin May 23, 1876 Mengel Aug. 7, 1883 Hopkes Sept. l0, 1940 Haberstump July 29, 1941 Bernstein Sept. 30, 1941 Heimerdinger Sept. 19, 1944 Williams et al. Oct. 17, 1950 Goldstein Apr. 17, 1951 FOREIGN PATENTS Country Date Great Britain Oct. 19, 1933 

